Nb₂O₅ is niobium pentoxide, a common measure of niobium content in ores. Niobium is used in high-strength steel alloys, superconductors, and in other high tech and industrial uses. Because the Araxá Project has both TREO and Nb₂O₅, it can produce rare earths and niobium as co-products, which improves the overall economic potential. https://colitco.com/st-george-delivers-high-grade-rare-earth-niobium/